This project investigates the relationship between migraine headache and other diseases based on the data collected from the large group of gravidae in the Collaborative Perinatal Project. Subgroups of women characterized by the absence and presence of migraine and other recurrent headaches prior to or during pregnancy, have been identified. Characteristics of these subgroups are being investigated on a variety of demographic, sociological, medical and obstetric factors, and the association of headache with other disorders is being examined. Preliminary results have shown that pregnant women with a migraine history had higher rates of smoking and of other symptoms and illnesses than women without a migraine history. Although there is no evidence that cigarette smoking might trigger or exacerbate migraine attacks in these women, smoking might have an additive effect on the association of migraine conditions with heart and thrombotic diseases, some respiratory and allergic diseases and peptic ulcer. Children of mothers with a history of migraine appear to have higher incidence of seizures and some infectious and allergic diseases than children born to mothers in the nonmigraine group. More intensive statistical analyses are being carried out to examine the apparent associations.